how many maximum 'acne' number in cosmetics ingredients that is safe to use? if my cream has a total 7 or 4 in acne, is it okay to use them?

I think everyone's acne triggers vary so what may be acnegenic for me may not be acnegenic for you. For instance, Ethylhexyl Palmitate has a 4 comedogenic rating but I can use it without issues but Chlorphenesin isn't even rated on here and it gives me acne. So be vary of the 4 and higher comedogenic rated ingredients but you won't know till you try it yourself

I agree that what breaks one person out may not break another out. I tend to not try anything over a 2 rating because my skin is really sensitive and breaks out easily. I read somewhere that a rating of 2 will not clog pores for most people but a rating of 3 a lot of people will break out but a lot of people may not break out. I hope that helps you decide.